Imagine you're sitting at a bar waiting for your freshly-dumped friend to arrive. She sits down in tears and announces that her boyfriend had a secret girlfriend all along. What would you do?

If you're Clara De Soto or Erica Mannherz, two smart girls who quit their jobs to start an innovative digital agency, you build an app for that. "[Our friend] was devastated, and was like, 'I want to start a website called your relationship is a sham dot com.' We didn't think that was a great idea (though someone less ethical did just that,) but we did see that she deactivated her Facebook account after this breakup, and so did other friends," explains De Soto. "We couldn't believe there wasn't a mechanism on Facebook that answered that—relationships end and that's a natural part of life. People shouldn't have to wade through the shards of their past relationships to see their friends' baby pictures on Facebook."

When KillSwitch—an app that is the digital equivalent of burning the evidence of your relationship—launched on Valentine's Day last year, it immediately went viral, which is no surprise, because, come on, is an explanation for why we need this in our social-media entrenched lives even necessary? We caught up with the founders one year later to discuss what it's like to be the sweethearts of the tech community, and how they answer the "what do you do?" question on dates.

KillSwitch came from kind of a dark place in your friend's life. Did your app make it better?

Clara De Soto: We've always maintained KillSwitch is a positive thing. We give a portion of proceeds to the American Heart Association, to reinforce that it's a healing mechanism. Every rom-com of the '90s has something like this-that process of getting over an ex. We definitely see a lot of new technologies that expect people to take new actions, but sometimes I don't want to do a new thing, I just need to do this existing thing better.

So what does KillSwitch do, and how are you upgrading it this Valentine's Day?

CD: KillSwitch lets you erase all evidence of an individual from your Facebook profile: You identify the target, select the posts you want gone, and hit the button. All the gushy status updates, kissy pictures, funny cat videos, you name it—gone in a flash.

The new update gives you the ability to KillSwitch people you aren't friends with. That's the natural progression of a breakup: first comes defriend, then comes KillSwitch. We're excited to be able to offer that. Our whole ethos is to have life dictating technology, not the other way around. Ultimately, we want you to be able to KillSwitch your life, say, pre-nose job, or whatever you want to remove. We want to bring all the best elements of Snapchatting to your Facebook.

What has the customer feedback been like? Do you get millions of scary emails from angry women? Are men using it too?

CD: You do have to be extra careful in making sure that our product works as well as possible, because our customers are not in the best mindset—when our users are unhappy, they're extremely vocal. We really wanted to cut down the wait time.

We don't have a real gender breakdown, but as people have reached out to us, it's been mostly dudes. Their comments tend to be a little curt. There's this natural assumption that women are the ones who will use this tool, but that hasn't really been the case.

Could you see KillSwitch working on other platforms?

CD: Yeah, our model would be interesting to explore on other platforms too, like Instagram—it's not even just romantic relationships, people have fallings out. In life you're supposed to be able to move on, and we're forced to carry this digital baggage. It's just an attempt to ease that burden. Everyone deserves a fresh start. High school kids don't even get that chance as they go into college; they start out knowing so much about each other.

You were both single when this app launched. How did you explain what you do to potential dates?

CD: We don't see this as a product we built for ourselves. My boyfriend and I were on-again, off-again, and when we started dating again and I saw his mom for the first time, I told her about this. She was like "Oh, I heard about this on the Today Show!" And then she was like "WAIT. What was the inspiration for this?" It wasn't her son, but I feel like it presents an interesting power dynamic in the relationship. It's surfaced in arguments, but it's been good—it's liberating! It's a tool people have in their back pocket. It's a digital pre-nup.

What surprised you most about the launch process?

Erica Mannherz: We feel like we've kind of pioneered the breakup app space, but the concept of managing your digital life, people haven't really put a toe in the water. The most surprising thing was when we watched it go viral—clearly we'd struck a chord that everyone could relate to. We couldn't believe it didn't exist yet. Even trying to explain it to older people, they got it immediately. It touches all walks of life.

How are you expanding KillSwitch's core concept to the rest of your business?

CD: Our program Total Recall is a program for events where we equip attendees with wristbands to engage with the event in a hands-free way. We worked at the South Beach Wine & Food Festival, where attendees wear this wristband and everything they try, they can tap a reader and store what they tried in a digital memory bank. For a big tasting like that, it's a lay-up. You wont remember anything otherwise because of the wine and all the food. It's a digital reaction to your offline action, in a really unobtrusive way. You don't even have to put down your burger! We're excited to be finalists at SXSW, and hopefully bring home a big prize.

How would you characterize your experience as women in the start-up world?

CD: It feels like the majority of women in tech are doing fashion start-ups, and none of them have done it that well yet. We play in that girlier space, but when they hear the full extent of it, it's really gotten us a seat at the table. We see a huge gap in the market, and there's a huge opportunity there. It's like shooting fish in a barrel.